This article presents two mathematical models for estimating the performances of finned tube heat exchangers with wavy configuration under partly and fully wet surface conditions. The actual dry bulb temperature method is the first one and the other is the method of equivalent dry bulb temperature. For the first one, the actual dry bulb temperature method that was firstly presented by our research team in 2015 is more uncomplicated than the well-known enthalpy potential method and is also easier than the equivalent dry bulb temperature method. Moreover, it has never been applicable to the finned tube heat exchanger. For accuracy, the finned tube heat exchangers are distinguished into teeny segments and every segments are separated by conditions of surface into three groups: partially wet segments, fully wet segments, fully dry segments. This procedure is called the finite circular fin method that was firstly presented by our research in 2007. From the results, the heat and mass transfer characteristics estimated by the method of equivalent dry bulb temperature are greater than those estimated by the method of actual dry bulb temperature. This is the influence of the non-constant terms in both methods. Moreover, the correlations for the conditions of party and fully wet surface are revealed for predicting the heat and mass transfer coefficients of the finned tube heat exchanger with wavy configuration. The users can apply our presented models with the proposed correlation for predicting the heat and mass transfer performances of finned tube heat exchangers with wavy configuration under the conditions of fully and partly wet surface. (C) 2016 Elsevier Ltd. All rights reserved.